Artificial Heart

Cardiovascular Medical Devices

  • Artificial heart

  • Heart-valve prostheses

  • Stents

No1 cause of death in the US?

  • Heart disease

Heart Disease

  • Congestive heart failure

    • steadily declining ability of the heart to pump blood

  • Heart Attacks

    • Blockage of coronary artery damages portion of heart muscle

  • Only final cure for heart failure is organ transplant

Heart=Pumps

  • A natural heart has two pumps, each with two chambers

  • The right atrium pumps oxygen-depleted blood from the body into the right ventricle, which pumps it to the lungs

  • the left atrium sends aerated blood from the lungs into the left ventricle, which pumps it out to the body

  • With each heart beat, the two atria contract together, followed by the large ventricles

Artificial Heart Functions

  • Design requirements of an artificial heart

    • maintains the hearts blood circulation and oxygenation for varying periods of time

    • Ideal artificial heart must beat 100,000 times/24 hours without requiring neither lubrication nor maintenance

    • must have a constant power source

    • must pump faster or slower depending on the activity of the patient without causing either infection or blood clots

    • weight, size

    • Provide adequate warning if something is wrong or if it is going to fail

    • should not evoke an immune response

    • should not produce blood clots

    • should not damage red blood cells

    • ideally should have pulsatile blood flow

Artificial Heart History

  • 1812 French physiologist replaced a heart with a pump

  • 1958: Drs. Willem Kolff and Tetsuzo Akutsu sustained a dog for 90 minutes with a PVC artificial heart

  • 1969: Dr. Denton Cooley uses an artificial heart to sustain a patient waiting for a donor (survived 3 days)

  • 1982: Jarvik 7, best known of the artificial heart device (named after its designer)

Jarvik 7

  • was designed by Robert Jarvik

  • 1982: Seattle dentist Dr. barney Clark was the first person implanted with the Jarvik-7, an artificial heart intended to last a lifetime

  • The patient survived 112 days.

  • 1985: 5 more were performed, longest 620 days

  • How it works

    • two pumps. Each sphere-shaped polyurethane “ventricle” has a disk -shaped mechanism that pushes the blood from the inlet valve to the outlet valve

  • Complications

    • Infection and thromboembolism

    • Materials and geometries are sites for thrombus formation

    • infection due to tubes and wires passing through skin

    • lack of pulsatile blood flow?

    • Withdrawal from the commercial market

The AbioCor Heart

  • Implantable replacement heart by ABIOMED

  • First completely self-contained total artificial hearts

  • First implant was in 2001 lasted 96 days

  • How it works